Electrophotographic processes for producing a permanent image on media are well known and commonly used. In general, these processes all include: (1) charging a photoreceptor which is a roller or continuous belt bearing a photoconductive material; (2) exposing the charged area to a light image to produce an electrostatic charge on the area in the shape of the image; (3) presenting developer particles (toner) to the photoreceptor surface bearing the image so that the particles are transferred to the surface in the shape of the image; (4) transferring the particles in the shape of the image from the photoreceptor to the media; (5) fusing or fixing the particles in the shape of the image to the media; and (6) cleaning or restoring the photoreceptor for the next printing cycle. Further information about alternative photographic processes is available in the text "The Physics and Technology of Xerographic Processes", by Edgar M. Williams, 1984, a Wiley-lnterscience Publication of John Wiley & Sons, the disclosure of which is hereby incorporated by reference.
Many image forming apparatus utilize the electrophotographic printing process, examples being laser printers, copy machines, and facsimile machines. As described above, these image forming apparatus use toner to print or copy the desired image or words onto a piece of paper or media. The toner is contained in a hopper, which must be refilled periodically. For example, the toner in a laser printer must be refilled after printing approximately 1000 pages.
The process of refilling the toner hopper has proven to be difficult and messy. Toner, the "ink" of the print or copy machine, is a powdery substance that must be applied evenly across the surface of the photoconductive drum during use. However, toner that leaks out of the hopper during shipping can accumulate on the drum and cause blotching, streaking or voiding of prints and copies. Toner leakage can also cause moving parts to wear out more rapidly and may even short out the electrical components in the cartridge. In these ways, toner leakage reduces the quality of prints and copies, increases maintenance cost, and can even decrease the useful life of the image forming machine.
To resolve the problems associated with toner refilling, a disposable toner cartridge is generally used. This cartridge typically includes a toner hopper, seal assembly, mounting member, magnetic roller assembly, photoconductive drum assembly and corona assembly. By combining these components in to a single cartridge, toner is applied equally across the surface of the drum without leaking out of the hopper during shipping. Unfortunately, this cartridge design is relatively expensive. In addition, the magnetic roller, drum and corona assemblies last considerably longer than 1000 pages. Thus, the disposal of the entire cartridge results in unnecessary waste of material and landfill space with the costs being passed on to the consumer.
Toner leakage is prevented by the seal assembly which is typically provided with a removable seal member. Once this seal member is removed, toner is allowed to flow out of the toner hopper opening onto the charged developer sleeve and across the surface of the drum as understood by one skilled in the art. Removal of the seal member also allows toner to permeate throughout the entire cartridge if shaken or flipped upside down. Consequently, the seal member is usually not removed until after the cartridge has been inserted into an image forming machine.
Presently, recycling the cartridge requires the recycles to collect old cartridges, bring them to their workshops, empty out waste toner and add new toner. The recycled cartridge are then deliver them back to the consumer. Attempts to do the same in the workplace, have resulted in problems particularly related to the inherent messiness of the procedure.